System for arranging and coupling battery cells in a battery module

ABSTRACT

A battery module includes a plurality of battery cells disposed in at least two rows. The battery cells in adjacent rows are offset from each other. Each of the plurality of battery cells includes a cover and a first terminal that extends from the cover outward. The first terminal is configured to be coupled to a second terminal on an adjacent battery cell. The plurality of battery cells are electrically coupled to each other in a zigzag pattern via the first and second terminals.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application is a Continuation-In-Part of U.S. patent applicationSer. No. 12/368,938 filed Feb. 10, 2009, which claims benefit of andpriority to U.S. Provisional Patent Application No. 61/101,985, filedOct. 1, 2008, and U.S. Provisional Patent Application No. 61/146,994,filed Jan. 23, 2009, and is also a Continuation-In-Part of InternationalApplication no. PCT/US2007/017785 filed Aug. 10, 2007, which claims thepriority to U.S. Provisional Patent Application No. 60/857,345, filedAug. 11, 2006, all of which are incorporated by reference in theirentireties for all purposes.

BACKGROUND

The present disclosure relates to the field of batteries and batterysystems. More specifically, the present disclosure relates to integrallyformed terminals for batteries or cells (e.g., lithium-ion batteries).

It is known to provide batteries or cells for use in vehicles such asautomobiles. For example, lead-acid batteries have been used instarting, lighting, and ignition applications. More recently, hybridelectric vehicles are being developed which utilize a battery (e.g., alithium-ion or nickel-metal-hydride battery) in combination with othersystems (e.g., an internal combustion engine) to provide power for thevehicle.

It is known that a battery generally includes two terminals (e.g., apositive terminal and a negative terminal, etc.) through which thebattery is electrically connected to other batteries or othercomponents. A battery may have terminals that protrude from the batterysurface and/or have a casing that acts as a terminal These terminals areprovided as separate elements that are coupled to the battery (e.g., bywelding to a battery cover). This adds an additional step to themanufacturing process, as well as increased cost. The integrity of thisweld or other coupling mechanism may present issues over the life of thebattery.

Battery systems or assemblies include a number of batteries or cellselectrically coupled to each other and/or to other elements of thesystem. Such cells are conventionally coupled together using conductivemembers (e.g., bus bars). Such conductive members may be welded to theterminals of the batteries or secured using fasteners. It would beadvantageous to eliminate the need for such conductive members to removethe additional cost and manufacturing time associated with suchcomponents (e.g., to reduce the number of parts in the battery systemand to eliminate the need to handle and assemble the components duringmanufacturing).

Accordingly, it would be advantageous to provide a battery that includesone or more terminals that are integrally formed with the body or coverof the battery. It would also be advantageous to configure the terminalsso they can be directly coupled to terminals of adjacent batteries.

SUMMARY

Certain embodiments commensurate in scope with the originally claimedsubject matter are summarized below. These embodiments are not intendedto limit the scope of the disclosure, but rather these embodiments areintended only to provide a brief summary of certain disclosedembodiments. Indeed, the present disclosure may encompass a variety offorms that may be similar to or different from the embodiments set forthbelow.

One embodiment relates to a battery including a housing having a centrallongitudinal axis. The battery also includes a cover coupled to thehousing and a first flange integrally formed with the cover. The firstflange is configured to act as a first terminal for the battery. Atleast a portion of the first flange extends away from the housing in adirection generally perpendicular to the central longitudinal axis. Thefirst flange is configured for electrical coupling with a terminal of anadjacent battery in a battery system.

Another embodiment relates to a battery module including a plurality ofelectrochemical cells. Each of the cells comprise a housing having alongitudinal axis and a lid coupled to the housing. The lid comprises amember configured to act as a first terminal for the cell. At least aportion of the member extends away from the housing in a directiongenerally perpendicular to the longitudinal axis. The member isconductively coupled to a terminal of an adjacent cell.

Another embodiment relates to a method of producing a battery moduleincluding providing a plurality of electrochemical cells. Each of thecells comprises a housing having a longitudinal axis and a cover coupledto the housing at a first end of the cell. The cover comprises a memberconfigured to act as a first terminal for the cell. At least a portionof the member extends away from the housing in a direction generallyperpendicular to the longitudinal axis. The method also includescoupling the member of one of the plurality of cells to a terminal of anadjacent cell.

BRIEF DESCRIPTION OF THE FIGURES

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a perspective view of a vehicle having a battery systemaccording to an embodiment;

FIG. 1A is a schematic cutaway view of a hybrid electric vehicleaccording to an embodiment;

FIG. 2 is a perspective view of a battery system according to anembodiment;

FIG. 2A is a cutaway perspective view of a battery system according toan embodiment;

FIG. 3 is a perspective view of a battery or cell according to anembodiment;

FIG. 4 is an exploded view of the battery of FIG. 3 according to anembodiment;

FIG. 5 is a perspective view of a cover for a battery according to anembodiment;

FIG. 6 is a top view of the cover of FIG. 5 according to an embodiment;

FIG. 7 is a cross-section view of the cover of FIG. 6 taken along line7-7 according to an embodiment;

FIG. 8 is a perspective view of a battery according to an embodiment;

FIG. 9 is a perspective view of the cover of the battery of FIG. 8according to an embodiment;

FIG. 10 is a view of multiple batteries connected together according toan embodiment;

FIGS. 11A-11G are views of a battery according to various embodiments;

FIG. 12 is an exploded view of a battery according to an embodiment;

FIG. 13 is an exploded view of a battery according to an embodiment;

FIG. 14 is a perspective view of a first electrochemical cell coupled toa second electrochemical cell with a bus bar according to an embodiment;

FIG. 15 is a perspective view of a bus bar coupled to a terminal of anadjacent electrochemical cell according to an embodiment;

FIG. 16 is a perspective view of a portion of a battery module having afirst electrochemical cell coupled to a second electrochemical cell withthe bus bar as shown in FIG. 15 according to an embodiment;

FIG. 17 is a cutaway perspective view of a portion of an electrochemicalcell shown without electrodes according to an embodiment;

FIG. 18 is an exploded view of the electrochemical cell as shown in FIG.17 according to an embodiment;

FIG. 19 is a perspective view of a lid having an integral bus barcoupled to a terminal according to an embodiment;

FIG. 20 is a perspective view of the lid as shown in FIG. 19 accordingto an embodiment;

FIG. 21 is a perspective view of a battery module according to anembodiment;

FIG. 22 is a perspective view of the battery module as shown in FIG. 21with an upper tray removed according to an embodiment;

FIG. 23 is a perspective view of a plurality of electrochemical cellsprovided in an upper tray according to an embodiment;

FIG. 24 is a perspective view of a plurality of electrochemical cellsprovided in an upper tray according to an embodiment;

FIG. 25 is a top view of the upper tray as shown in FIG. 21 according toan embodiment;

FIG. 26 is a perspective view of the upper tray as shown in FIG. 21according to an embodiment;

FIG. 27 is a bottom view of the upper tray as shown in FIG. 21 accordingto an embodiment;

FIG. 28 is a bottom perspective view of the upper tray as shown in FIG.21 according to an embodiment;

FIG. 29 is a top view of an arrangement of battery cells in a batterymodule according to an embodiment;

FIG. 30 is a top view of another arrangement of battery cells in abattery module according to an embodiment; and

FIG. 31 is a top view of another embodiment of battery cells in abattery module according to an embodiment.

DETAILED DESCRIPTION

Referring to FIG. 1, a vehicle 12 is shown according to an embodimentand includes a battery system 14. The size, shape, configuration, andlocation of battery system 14 and the type of vehicle 12 may varyaccording to various embodiments. For example, while vehicle 12 in FIG.1 is shown as an automobile, according to various embodiments, vehicle12 may comprise a wide variety of differing types of vehicles including,among others, motorcycles, buses, recreational vehicles, boats, and thelike. According to an embodiment, vehicle 12 has a battery system 14 forproviding all or a portion of the motive power for the vehicle 12. Sucha vehicle can be an electric vehicle (EV), a hybrid electric vehicle(HEV), a plug-in hybrid electric vehicle (PHEV), or other type ofvehicle using electric power for propulsion (collectively referred to as“electric vehicles”).

Although the battery system 14 is illustrated in FIG. 1 as beingpositioned in the trunk or rear of the vehicle 12, according to otherembodiments, the location of the battery system 14 may differ. Forexample, the position of the battery system 14 may be selected based onthe available space within the vehicle 12, the desired weight balance ofthe vehicle 12, the location of other components used with the batterysystem 14 (e.g., battery management systems, vents or cooling devices,etc.), and a variety of other considerations.

FIG. 1A illustrates a cutaway schematic view of a vehicle 100 providedin the form of a PHEV according to an embodiment. A battery system 102is provided toward the rear of the vehicle 100 proximate to a fuel tank104 (battery system 102 may be provided immediately adjacent to the fueltank 104 or may be provided in a separate compartment in the rear of thevehicle 100 (e.g., a trunk) or may be provided elsewhere in the vehicle100). An internal combustion engine 106 is provided for times when thevehicle 100 utilizes gasoline power to propel itself. An electric motor108, a power split device 112, and a generator 114 are also provided aspart of the vehicle drive system of vehicle 100. The vehicle 100 may bepowered or driven by just the battery system 102, by just the engine106, or by both the battery system 102 and the engine 106.

It should be noted that other types of vehicles and configurations forthe vehicle electrical system may be used according to otherembodiments, and that the schematic illustration of FIG. 1A should notbe considered to limit the scope of the subject matter described in thepresent application.

Referring to FIG. 2, battery system 14 is shown according to anembodiment. Battery system 14 includes a plurality of electrochemicalcells or batteries, shown as batteries 10 (e.g., lithium-ion batteries,NiMH batteries, lithium polymer batteries, etc.). Batteries 10 may bepositioned within a housing that may include such features as a batterymanagement system, a cooling fan, plenum assembly, etc. Otherconfigurations of battery system 14 may be used in accordance withvarious other embodiments.

Referring to FIG. 2A, a battery system 116 is shown according to anembodiment and is responsible for packaging or containing a batterymodule 117 containing electrochemical cells or batteries 118, connectingthe electrochemical cells 118 to each other and/or to other componentsof the vehicle electrical system, and regulating the electrochemicalcells 118 and other features of the battery system 116. For example, thebattery system 116 may include features that are responsible formonitoring and controlling the electrical performance of the batterysystem 116, managing the thermal behavior of the battery system 116,containment and/or routing of effluent (e.g., gases that may be ventedfrom a cell 118), and other aspects of the battery system 116.

Referring to FIG. 2A, the battery module 117 includes a plurality ofelectrochemical cells or batteries 118 (e.g., lithium-ion batteries,nickel-metal-hydride cells, lithium polymer cells, etc., or other typesof electrochemical cells now known or hereafter developed). According toan embodiment, the electrochemical cells 118 are generally cylindricallithium-ion cells configured to store an electrical charge. According toother embodiments, cells 118 could have other physical configurations(e.g., oval, prismatic, polygonal, etc.). The capacity, size, design,and other features of the cells 118 may also differ from those shownaccording to other embodiments. According to an embodiment, the cells118 each have at least one terminal 119 located at an end thereof.According to another embodiment, the cells each have two terminals 119(e.g., a first or positive terminal, and a second or negative terminal)located at an end thereof.

According to various embodiments, the size, shape, and location of thebattery module 117 or battery system 116, the type of vehicle 100, thetype of vehicle technology (e.g., EV, HEV, PHEV, etc.), and the batterychemistry, among other features, may differ from those shown ordescribed.

Although illustrated in FIG. 2A as having a particular number ofelectrochemical cells 118, it should be noted that according to otherembodiments, a different number and/or arrangement of electrochemicalcells 118 may be used depending on any of a variety of considerations(e.g., the desired power for the battery system 116, the available spacewithin which the battery system 116 is designed to fit, etc.).

According to an embodiment, a series of members or elements in the formof trays 140 or similar structures are provided to contain the variouscells 118 in relation to each other. The trays 140 may be made of apolymeric material or other suitable materials (e.g., electricallyinsulative materials). The trays 140 may also include features toprovide spacing of the cells 118 away from the surface of the trays 140and/or from adjacent cells 118. A housing or cover 142 and a base plate(not shown) may be provided to partially or completely surround orenclose the cells 118 and trays 140.

While FIG. 2A shows an embodiment of a battery module 117, it should beunderstood that the battery module 117 is not limited to any particulararrangement as will be appreciated by those reviewing this disclosure.For instance, while the battery module 117 shown in FIG. 2A is shownwith horizontally oriented cells 118 arranged back-to-back in two banksor groups by parallel frame members (i.e., trays 140), it should beunderstood that the battery module 117 may have many differentconfigurations. For example, the cells 118 may also be generallyvertical, be several separate groups, or arranged in otherconfigurations. Furthermore, different numbers and types (e.g.,nickel-metal-hydride, etc.) of cells 118 may be used. The cover 142 mayinclude features (e.g., sidewalls, etc.) that are intended to receiveand arrange the cells 118.

Referring now to FIGS. 3-4, a battery or cell 10 is shown according toan embodiment. Battery 10 is generally cylindrical and comprises acontainer 20 (e.g., housing, casing, can, etc.), a cover or lid 30coupled to container 20, a member or element in the form of an insulator40 that separates container 20 and cover 30, and one or more terminals50. Container 20 is a generally hollow body (e.g., can, cup, canister,etc.) made of aluminum or another conductive material. Container 20 hasprovided therein electrodes 60 and an electrolyte (not shown) and mayact as a terminal 50 for battery 10. According to an embodiment, battery10 is a lithium-ion battery, although those reviewing this disclosurewill recognize that other types of batteries may also use featuresdescribed herein (e.g., nickel-metal-hydride batteries, lithium-polymerbatteries, etc.).

Cover 30 is a generally planar member or element (e.g., lid, cap, top,etc) that encloses electrodes 60 and the electrolyte in container 20 andis conductively separated from container 20 by insulator 40. Accordingto an embodiment, cover 30 is aluminum or another suitable conductivematerial and is conductively coupled to electrode 60 in battery 10.

Referring to FIGS. 5-7, according to an embodiment, terminal 50 is aprotrusion or extension that is extruded, drawn, molded, cast, orotherwise formed as an integral part of cover 30. According to otherembodiments, terminal 50 may be a variety of shapes other than thatshown in FIGS. 5-7 (e.g. cylindrical, rectangular, trapezoidal, etc.)and may be provided in a variety of positions (e.g., central, near theedge, etc.) and orientations. According to still other embodiments,terminal 50 may be provided on container 20 or terminals 50 may beprovided both on container 20 and on cover 30. Terminal 50 may befurther machined or shaped to provide a feature for coupling terminal 50to wires, sockets, bus bars, or other components. It should be notedthat terminal 50 can either follow the contour of the cover 30 or can beflattened so that a standard spade connector can be placed flat on thesurface of the terminal 50 according to other embodiments.

Referring now to FIG. 8, a battery 110 is shown according to anembodiment. Battery 110 is generally cylindrical and comprises acontainer or housing 120 and a cover or lid 130 coupled to container120. Container 120 is a generally thin-walled hollow body (e.g., a can,cup, canister, etc.) made of aluminum or another conductive material andis conductively coupled to an electrode (e.g., cathode or anode).Container 120 holds electrodes and an electrolyte (not shown) and mayact as a terminal for battery 110. Container 120 includes a side wall122 with a rim 123. Container 120 also includes a feature shown as aflange 124 (e.g., a tab, flap, projection, extension, protrusion,projection, lip, overhang, protuberance, etc.).

Flange 124 is a generally flat member (e.g., a tab, flap, projection,extension, protrusion, projection, lip, overhang, protuberance, etc.)that is integrally formed with side wall 122 and extends upward past rim123. Flange 124 may be bent and have a vertical portion 126 and ahorizontal portion 128 that extends beyond side wall 122 (e.g., in adirection generally perpendicular to the axial or longitudinal directionfor the cell). Flange 124 is configured to engage flange 134 on cover130 of an adjacent battery 110 (described in more detail below withrespect to FIG. 10).

Cover 130, as shown in FIG. 9, is a generally flat body (e.g., lid, cap,top, etc.) that encloses electrodes and electrolyte in container 120 andis conductively separated from container 120 with an insulator (notshown). According to an embodiment, cover 130 is aluminum or anothersuitable conductive material and is conductively coupled to an electrodein battery 110. Cover 130 comprises a generally flat, circular surfaceor body 132, and a generally vertical side wall 133 that extends upwardfrom and substantially perpendicular to surface 132. Side wall 133 is acurved feature that substantially follows the contour of side wall 122of container 120 and has an outer diameter less than the inner diameterof side wall 122. Cover 130 is configured to fit inside the open end ofcontainer 120. Cover 130 also includes a feature shown as flange 134.

Flange 134 is a generally flat member (e.g., tab, flap, projection,extension, etc.) that is integrally formed with side wall 133 andextends upward therefrom. Flange 134 may be bent and have a verticalportion 136 and a horizontal portion 138 that extends outward past sidewall 133 in a direction generally opposite horizontal portion 128 offlange 124.

Referring now to FIG. 10, a plurality of batteries 110 are shownconnected in series to form a portion of a battery module or batterysystem. According to an embodiment, vertical portion 136 of flange 134on cover 130 is longer than vertical portion 126 of flange 124 oncontainer 120. When a first battery 110 is coupled to a second battery110 (e.g., by welding), horizontal portion 138 of flange 134 on onebattery 110 rests on horizontal portion 128 of flange 124 on anotherbattery 110. According to an embodiment, flanges 124, 134 are weldedtogether. According to other embodiments, flanges 124, 134 may becoupled in another suitable manner, either permanently or temporarily(e.g., bolted, riveted, crimped, clamped, etc.). Flanges 124, 134 mayact as terminals that can directly and conductively couple two batteriestogether, eliminating the need for a separate member to conductivelycouple the batteries.

Referring now to FIGS. 11A-11G, a number of batteries are shownaccording to various embodiments. Each battery comprises a firstterminal and a second terminal According to the various embodiments, oneor both of the terminals may be integrally formed as a part of the coverand/or container of the battery. FIG. 11A illustrates a battery 210 withterminals 220, 230 that are located on the same end of battery 210 andare substantially smooth pins. FIG. 11B illustrates a battery 310 with afirst terminal 320 on one end and a second terminal 330 on an oppositeend. According to an embodiment, terminals 320, 330 are substantiallysmooth pins.

FIG. 11C shows an embodiment of a battery 410 with terminals 420, 430that are located on the same end of battery 410 and are generally thinflat members (e.g., blades). According to an embodiment, terminals 420,430 are generally parallel. According to other embodiments, terminals420, 430 may be at some other angle relative to each other (e.g.,perpendicular to each other as in FIG. 11D).

FIG. 11E shows an embodiment of a battery 510 with a first terminal 520on one end and a second terminal 530 on an opposite end. Terminals 520,530 are generally thin flat members (e.g. blades).

FIG. 11F shows an embodiment of a battery 610 with terminals 620, 630that are located on the same end of battery 610 and are generally thinflat members bent into a generally L-shaped profile. According to anembodiment, first terminal 620 and second terminal 630 are bent suchthat the horizontal portions of terminals 620, 630 extend toward andbeyond the periphery of battery 610. First terminal 620 and secondterminal 630 are configured to have horizontal portions of slightlydifferent lengths such that first terminal 620 on one battery 610 mayrest on second terminal 630 of an adjacent battery 610.

FIG. 11G shows an embodiment of a battery 710 with a first terminal 720on one end and a second terminal 730 on an opposite end. Terminals 720,730 are generally thin flat members bent into a generally L-shapeprofile. According to an embodiment, terminals 720, 730 are bent suchthat the horizontal portions of terminals 720, 730 extend in the samedirection. According to other embodiments, terminals 720, 730 may bebent in opposite directions or may extend at some other angle relativeto each other.

Referring to FIG. 12, a battery 810 is shown according to an embodimentand includes a top portion, or cover 830, a bottom portion, or container820, and a seal portion 860. According to an embodiment, cover 830 isprovided with raised portions or terminals 840, 850 that may act aspositive and/or negative terminals for battery 810. Terminals 840, 850may be integrally formed with cover 830 (e.g., not welded) so as toreduce manufacturing costs and the number of component parts associatedwith battery 810.

As shown in FIG. 12, seal 860 may be applied around the upper portion ofcontainer 820. According to an embodiment, seal 860 comprises a polymermaterial such as a polyethylene, etc. According to various embodiments,other materials may be used to make seal 860. Seal 860 may be providedin a tape or strip form and wrapped around container 820 as shown inFIG. 12 and, in some instances, held in place with an adhesive (e.g.,either as an integral part of seal 860 or as a separately providedcomponent).

According to an embodiment, in order to attach cover 830 to container820, cover 830 is first heated to expand the inside diameter of cover830. While in the expanded condition, cover 830 is fitted over container820 and seal 860 such that the heat from cover 830 at least partiallymelts seal 860, thereby helping to seal cover 830 to container 820. Ascover 830 is allowed to cool, cover 830 contracts while positioned overcontainer 820, forming a tight, sealed joint between cover 830 andcontainer 820.

According to an embodiment, the inside diameter of cover 830 isapproximately the same as the outside diameter of container 820, therebyproviding a secure fit between cover 830 and container 820 aftercoupling of cover 830 to housing 820. According to various embodiments,the dimensions of cover 830 and/or container 820 may be varied toprovide a more or less snug fit for various applications. Furthermore,seal 860 may be provided on cover 830 rather than container 820.

According to an embodiment, seal 860 is configured to act as a vent forbattery 810. For example, seal 860 may deteriorate (e.g., melt, etc.) asa result of the pressure and/or temperature within battery 810 reachinga predetermined level, thereby permitting pressurized gases or otherfluids to escape from within battery 810. This provides for a method ofventing battery 810 that avoids the expense and time of manufacturingand assembling separate components to provide for venting of battery810.

As shown in FIG. 12, battery 810 is provided as a generally cylindricalbattery having a generally circular cross-section. Terminals 840, 850shown in FIG. 12 are integrally formed with cover 830. Cover 830 may beeither conductively coupled to or insulated from container 820.According to various other embodiments, battery 810 may take othershapes and forms, and terminals 840, 850 may be provided as integrallyformed terminals in a variety of locations.

Referring now to FIG. 13, a battery 910 is shown according to anembodiment. As shown in FIG. 13, battery 910 includes a cover 930 and acontainer 920. According to an embodiment, container 920 includesterminals 940, 950 that may be integrally formed with container 920. Aseal 960 that may be similar to seal 860 discussed with respect to FIG.12 is provided around the lower portion of container 920 to seal cover930 to container 920 in a manner similar to that discussed with respectto FIG. 12.

According to an embodiment, battery 910 is similar to battery 810 andmay be manufactured and assembled in a similar manner except thatterminals 940, 950 are integrally formed with container 920 (rather thanwith cover 930), and cover 930 is intended to engage the bottom portionof container 920 (rather than the top portion as shown in FIG. 12).Furthermore, battery 910 is provided with an elongated (e.g., oval,etc.) cross-section, rather than the generally circular cross-section ofbattery 810. According to various other embodiments, other modificationsmay be made to batteries 810, 910 in order to accommodate variousspecific applications. For example, seals 860, 960 may be reinforced byother methods of sealing (e.g., laser welding, sonic welding, adhesives,etc.).

Referring now to FIG. 14, a method of connecting the terminals 1012,1014 of adjacent cells 1010 is shown according to an embodiment. Each ofthe cells 1010 are electrically coupled to one or more other cells 1010or other components of the battery system 116 (shown, e.g., in FIG. 2A)using connectors provided in the form of bus bars 1016 or similarelements. For example, FIG. 14 shows two cells 1010 coupled togetherwith a bus bar 1016 according to an embodiment. A portion of the bus bar1016 is shown as a broken view to show the interface between the bus bar1016 and the terminal 1012. The bus bar 1016 is a metallic member (e.g.,copper, copper alloy, aluminum, aluminum alloy, etc.) that couples thenegative terminal 1014 of a first cell 1010 to the positive terminal1012 of a second cell 1010. The bus bar 1016 includes a first end 1018that is coupled to the negative terminal 1014 of the first cell 1010(e.g., by an interference fit, by welding, etc.) and a second end 1020that is coupled to the positive terminal 1012 of a second cell 1010(e.g., by an interference fit, by welding etc.).

The first end 1018 and the second end 1020 of the bus bar 1016 eachinclude a projection 1022 (e.g., protruding ridge, lip, flange,extension, etc.) that is configured to substantially surround theterminal 1012, 1014 of a cell 1010. The projection 1022 may be cast orformed by a mechanical process such as a stamping operation, a punchingoperation, or an extrusion operation. The mechanical process causes theprojection 1022 to extend outward from the top surface 1024 of the busbar 1016. The projection 1022 forms a generally vertical wall 1026 thatdefines an aperture 1028 that is configured to receive the terminal1012, 1014 of the projection 1022.

According to an embodiment, the aperture 1028 has a diameter that issmaller than the diameter of the terminal 1012, 1014 so that the bus bar1016 is coupled to the cell 1010 with an interference fit when theterminal 1012, 1014 is received by the aperture 1028. The bus bar 1016is assembled with the cells 1010 by first heating the bus bar 1016(e.g., by induction heating, by an oven, by a flame or heating element,etc.). According to an embodiment, the heating of the bus bar 1016occurs as part of an assembly line process where the bus bars 1016 beingare heated (e.g., in an oven) in the assembly line and directlyassembled with the cells 1010.

According to an embodiment, the bus bar 1016 is heated to a temperaturesufficient to expand the material of the bus bar 1016, widening theaperture 1028 formed by the projection 1022 and allowing the terminal1012, 1014 to be received by the aperture 1028 in the bus bar 1016.According to various embodiments, these temperatures may vary dependingon the material properties of the bus bars 1016 (e.g., coefficient ofthermal expansion). As the bus bar 1016 cools, the diameter of theaperture 1028 shrinks, forming an interference fit with the terminal1012, 1016. An insulator 1132 (e.g., as shown in FIG. 15) may beprovided below the bus bar 1016 and around the terminal 1012, 1014 toreduce the chance of inadvertent contact between the bus bar 1016 andthe lid or cover 1034 of the cell 1010.

The bus bar 1016 may be further coupled to the cell 1010 with a weldingoperation such as an ultrasonic welding operation, a laser weldingoperation, or a resistance welding operation. According to an anotherembodiment, the bus bar 1016 may be welded to the terminals 1012, 1014of the cells 1010 instead of being provided with an interference fit andwelded to the terminals 1012, 1014 of the cells 1010. According to ananother embodiment, the bus bar 1016 may be press fit to the terminals1012, 1014 of the cells 1010 instead of being welded to the terminals1012, 1014 of the cells 1010.

FIGS. 15-16 show a bus bar 1116 according to another embodiment coupledto a terminal 1112 of a cell 1110. A portion of the bus bar 1116 isshown as a broken view to show the interface between the bus bar 1116and the terminal 1112. The bus bar 1116 is a metallic member (e.g.,copper, copper alloy, aluminum, aluminum alloy, etc.) that couples afirst cell 1110 to a second cell (e.g., as shown in FIG. 16). The busbar 1116 includes a first end 1118 that is coupled to a terminal 1112 ofthe first cell 1110 (e.g., by an interference fit, by welding, etc.) anda second end 1120 that is coupled to the housing 1136 of the second cell1110 (e.g., by a press fit, by an interference fit, by welding, etc.).The first end 1118 of the bus bar 1116 shown in FIG. 15 is similar tothe first end 1018 of the bus bar 1016 shown in FIG. 14. However, thesecond end 1120 of the bus bar 1116 shown in FIG. 15 is configured to becoupled to the housing 1136 of a second, adjacent cell 1110 and to actas a cover for the second cell.

The first end 1118 of the bus bar 1116 includes a projection 1122 (e.g.,protruding ridge, lip, flange, extension, etc.) that is configured tosubstantially surround the terminal 1112 of a first cell 1110. Theprojection 1122 may be cast or may be formed by a mechanical processsuch as a stamping operation, a punching operation, or an extrusionoperation. The mechanical process causes the projection 1122 to extendoutward from a top surface 1124 of the bus bar 1116. The projection 1122forms a generally vertical wall 1126 that defines an aperture 1128 thatis configured to receive the terminal 1112 of the cell 1010. In otherwords, the terminal 1112 is received in the aperture 1128 defined by theprojection 1122 of the bus bar 1116 such that contact is made betweenthe terminal 1112 and an inner surface 1130 of the projection 1122.

FIG. 16 shows a portion of a battery module including two cells 1110coupled together with the bus bar 1116 of FIG. 15. The cells 1110 aregenerally cylindrical bodies with a top or first surface 1134 having aterminal 1112 (e.g., a negative terminal, a positive terminal) thatextends generally upward from the top surface 1134. The terminal 1112 iselectrically coupled to a first electrode (not shown) inside the housing1136 of the cell 1110 (e.g., a negative electrode, a positiveelectrode). However, the terminal 1112 is electrically insulated fromthe housing 1136 itself (e.g., by an insulator 1132). The housing 1136of the cell 1110, including the top surface 1134 of the cell 1110, iselectrically coupled to a second electrode (not shown) inside thehousing 1136 of the cell 1010 (e.g., a positive electrode, a negativeelectrode).

The bus bar 1116 is coupled to the cells 1110 by first coupling thesecond end 1120 of the bus bar 1116 to the top surface 1134 of the ofthe second cell 1110. According to an embodiment, the second end 1120 ofthe bus bar 1116 is press fit into the top of the housing 1136 of thesecond cell 1110 and then welded (e.g., ultrasonic, laser, resistance,etc.) to form a cover for the cell 1110 (i.e., the cover includes anextension or flange that acts as a bus bar or terminal for coupling toan adjacent cell). According to another embodiment, the second end 1120of the bus bar 1116 is larger than the diameter of the top of the secondcell 1110 and is coupled to the top of the second cell 1110 with aninterference fit. The second end 1120 of the bus bar 1116 is shrunk(e.g., reduced in size, made smaller, etc.) by a cooling process (e.g.,using liquid nitrogen). The second end 1120 of the bus bar 1116 is thenplaced into the open end of the top of the second cell 1110 and allowedto return to room temperature. The second end 1120 of the bus bar 1116may then be further coupled to the cell 1110 by a welding operation suchas an ultrasonic welding operation, a laser welding operation, or aresistance welding operation.

The first end 1118 of the bus bar 1116 is then coupled to the terminal1112 of the first cell 1110. According to an embodiment, the first end1118 of the bus bar 1116 is welded (e.g., ultrasonic, laser, resistance,etc.) to the terminal 1112 of the first cell 1110. According to anotherembodiment, the first end 1118 of the bus bar 1116 is press fit to theterminal 1112 of the first cell 1110. According to another embodiment,the aperture 1128 in the first end 1118 of the bus bar 1116 has adiameter that is smaller than the diameter of the terminal 1112 so thatthe first end 1118 of the bus bar 1116 is coupled to the terminal 1112of the first cell 1110 with an interference fit. The first end 1118 ofthe bus bar 1116 is heated (e.g., by placing the first end 1118 near aheating element or a flame). Heating the first end 1118 of the bus bar1116 expands the metal, widening the aperture 1128 formed by theprojection 1122 and allowing the terminal 1112 to be received in theaperture 1128 in the first end 1118 of the bus bar 1116. As the bus bar1116 cools, the diameter of the aperture 1128 shrinks, forming aninterference fit with the terminal 1112. An insulator 1132 (e.g., asshown in FIG. 16) may be provided below the bus bar 1116 and around theterminal 1112 to reduce the chance of inadvertent contact between thebus bar 1116 and the housing 1136 of the cell 1010. The bus bar 1116 maythen be further coupled to the terminal 1112 of the cell 1010 with awelding operation such as an ultrasonic welding operation, a laserwelding operation, or a resistance welding operation.

Referring now to FIGS. 17-18, a cell can or housing 1212 (e.g., acontainer, casing, etc.) for an electrochemical cell 1210 is shownaccording to an embodiment. The housing 1212 is configured to receive orhouse a cell element (e.g., a wound cylindrical cell element) that isnot shown. According to an embodiment, the housing 1212 comprises athree-piece structure, comprising a main body 1214 (that may, e.g., bemade from an aluminum tube or tubing), a first cover or bottom 1216, anda second cover or lid 1218 that includes a flange (e.g., a tab, flap,projection, extension, protrusion, projection, lip, overhang,protuberance, etc.) that acts as a bus bar or terminal for coupling thecell 1210 to a terminal of an adjacent cell.

As shown in FIG. 18, the three-piece housing 1212 provides for aflexible design that may be varied (e.g., in length) to provide forvarious sizes and capacities of cell elements. For example, a differentlength main body 1214 may be used with the same bottom 1216 and lid1218. Additionally, internal connections (e.g., current collectors,etc.) may be changed for different applications without affecting thedesign of the external interface (e.g., the lid 1218, the bus bars 1226,etc.) of the module that the cells 1210 are provided in. Furthermore,this type of separate component design allows for lower cost tooling fordevelopment and higher efficiencies in economies of scale in that thesame design for the bottom 1216 and the lid 1218 may be usedinterchangeably with different lengths of the main body 1214.

According to an embodiment, the separate components (i.e., the main body1214, bottom 1216, and lid 1218) are easier to clean and handle thanprevious designs. For example, the main body 1214, bottom 1216, and lid1218 may be cleaned separately and then assembled together. Previousdesigns having the bottom or the lid integral with the main body made itdifficult to clean the inside of the main body and/or the bottom or lid.Having separate components allows for full accessibility to thecomponents of the housing 1212.

Referring now to FIG. 18, the bottom 1216 may have an integral ventfeature 1220 according to an embodiment. The vent feature 1220 may beconfigured to separate or deploy from the bottom 1216 if the pressureinside the housing 1212 reaches a predetermined amount. Various sizedvents 1220 may be used with the bottom 1216, allowing different internalpressures to be obtained depending on the design (e.g., size) of thevent 1220 used. Additionally, the various sized vents 1220 may beinterchanged with different sized housings 1212, dependent upon theneeds of the application. According to an embodiment, the bottom 1216 iscoupled (e.g., by a welding process, such as laser welding) to a lowerportion of the housing 1212.

Referring to FIGS. 19-20, the cover 1218 or lid for the housing 1212 isshown according to an embodiment. The lid 1218 includes a first terminal1222 (e.g., a positive terminal) that may be provided, for example, inthe center of the lid 1218. The first terminal 1222 is insulated fromthe lid 1218 by the use of an insulating material or insulating deviceshown as an insulator 1224. The first terminal 1222 may be coupled to anelectrode (e.g., a positive electrode) of the cell element (not shown)with a current collector (not shown). According to an embodiment, thelid 1218 is coupled (e.g., by welding process, such as laser welding) toan upper portion of the housing 1212.

Still referring to FIGS. 19-20, the lid 1218 also comprises a membershown as a flange (e.g., a tab, flap, projection, extension, protrusion,projection, lip, overhang, protuberance, etc.) that may act as aterminal or bus bar 1226 for the cell 1210. According to an embodiment,the bus bar 1226 is integral with the lid 1218 (i.e., the bus bar 1226and lid 1218 are a single unitary body). Having the bus bar 1226integral with the lid 1218 reduces the overall component count of thesystem. Additionally, the number of fasteners (not shown) used (e.g., tocouple the bus bars 1226 to the terminals 1222) is reduced. Furthermore,the overall system cost may be reduced by eliminating or reducing theamount of copper used by having integral bus bars 1226.

As shown in FIGS. 19-20, the bus bar 1226 extends out and away from thelid 1218. According to an embodiment, the bus bar 1226 is at a heightthat is different (i.e., higher) than the height of the lid 1218,allowing the bus bar 1226 to be placed over (i.e., on top of) a terminal1222 of an adjacent cell 1210. The bus bar 1226 is configured with anaperture 1228 at an end of the of the bus bar 1226. According to anembodiment, the aperture 1228 is configured to allow a fastener (notshown) to be placed through the aperture 1228 in order to couple the busbar 1226 to a terminal 1222 of an adjacent cell 1210.

According to another embodiment, the lid 1218 may also comprise anaperture or hole shown as fill hole 1230. Fill hole 1230 is configuredto allow a substance (e.g., electrolyte) to be placed in the cell 1210after the cell 1210 is assembled. According to another embodiment, thelid may also comprise an aperture or hole 1234 (e.g., as shown in FIG.20) configured to receive the first terminal 1222 and insulator 1224.

According to another embodiment, the bus bar 1226 may function as asecond terminal 1232 (e.g., a negative terminal) of the cell 1210 due tothe fact that the bus bar 1226 may be electrically connected to anelectrode (e.g., a negative electrode) of the cell element (not shown).The bus bar 1226, being integral with the lid 1218, may be connected tothe electrode by the lid 1218 being electrically connected to the mainbody 1214 of the housing 1212. The main body 1214 of the housing 1212 iselectrically connected to the bottom 1216 of the housing 1212, which inturn is then electrically connected to the electrode of the cellelement, completing the connection from the bus bar 1226 to theelectrode.

Referring now to FIGS. 21-24, a battery module 1300 utilizing cells 1310having lids 1312 with integral terminals or bus bars 1314 is shownaccording to an embodiment. The battery module 1300 may be electricallycoupled with other battery modules 1300 to form a battery system (notshown) or may be used independently to form its own battery system. Thebattery system may include other features (not shown) that areresponsible for monitoring and controlling the electrical performance ofthe system, managing the thermal behavior of the system, containmentand/or routing of effluent (e.g., gases that may be vented from a cell1310), and other aspects of the battery module 1300 or battery system.

As shown in FIG. 21, the battery module 1300 includes a plurality ofelectrochemical cells 1310 each having a flange (e.g., a tab, flap,projection, extension, protrusion, projection, lip, overhang,protuberance, etc.) shown as an integral terminal or bus bar 1314 formedin the lid 1312 of the cell 1310, a first structure or upper tray 1316,and a second structure or the lower tray 1318. The plurality of cells1310 are provided in between the upper tray 1316 and the lower tray1318. Although illustrated in FIG. 21 as having a particular number ofelectrochemical cells 1310, it should be noted that according to otherembodiments, a different number and/or arrangement of electrochemicalcells 1310 may be used depending on any of a variety of considerations(e.g., the desired power for the battery module 1300, the availablespace within which the battery module 1300 is designed to fit, etc.).

According to an embodiment, the upper tray 1316 comprises features 1320(e.g., raised portions, cutouts, channels, spaces, molded areas, etc.)that receive the integral bus bars 1314 of the individual cells 1310 toproperly orientate or align the cells 1310 (and the integral bus bars1314) so that the bus bars 1314 are properly aligned to be connected toan adjacent cell 1310. The upper tray 1316 also comprises a featureshown as a wall 1322 (as shown, e.g., in FIG. 24) that partiallysurrounds the upper portion of the cell 1310 to aid in properly locatingthe cell 1310. It should be noted that the bus bars 1314 used inconnection with the upper tray 1316 need not be integral with the lid1312 (i.e., the upper tray 1316 will still be able to properly align andorientate cells 1310 having non-integral bus bars 1314).

According to another embodiment, the upper tray 1316 also comprisesopenings or apertures 1324 that expose a portion of the bus bar 1314(e.g., the end of the bus bar 1314 having an aperture 1326) to becoupled (e.g., with a fastener, by welding, etc.) to a terminal 1328 ofan adjacent cell 1310. According to an embodiment, the terminal 1328 ofthe adjacent cell 1310 is threaded (e.g., to receive a fastener 1329, asshown in FIG. 22). According to another embodiment, the terminal 1328 ofthe adjacent cell 1310 may be flat so that the terminal 1328 may bewelded to the bus bar 1314. The upper tray 1316 may be made of a polymer(e.g., polypropylene, polyethylene, etc.) or any other suitable material(e.g., insulative material).

Still referring to FIG. 21, the battery module 1300 is shown to includea seal 1330 provided along an upper surface of the lower tray 1318 inorder to seal a chamber (not shown) located inside the lower tray 1318.According to an embodiment, the seal 1330 is configured to seal the gapbetween the lower portion of the cells 1310 and the lower tray 1318(when the cells 1310 are placed in the lower tray 1318). According to anembodiment, the seal 1330 may be constructed from silicone (e.g., moldedsilicone) or other appropriate material.

According to an embodiment, the seal 1330 is configured to aid incontaining any gases that are vented from the cells 1310 into thechamber. For example, gases may be vented from the cells 1310 via a ventdevice or vent feature 1334 located at the lower end of each of thecells 1310 (shown, e.g., in FIGS. 23-24). According to anotherembodiment, an opening or outlet 1336 (e.g., as shown in FIG. 21) may beprovided in fluid connection with the chamber. The outlet 1336 may beused to direct gases from the chamber (after having been vented from thecells 1310) to outside the battery module 1300 (e.g., outside thevehicle).

Referring now to FIG. 22, the battery module 1300 is shown with theupper tray 1316 removed. As can be seen in FIG. 22, the bus bars 1314 ofthe cells 1310 are properly oriented so that they are ready forconnection to a terminal 1328 of an adjacent cell 1310 (or forconnection to another module 1300 or other component of the batterysystem). According to another embodiment, the battery module 1300 mayalso include an aperture or hole shown as fill hole 1332 in the lid 1312of the cell 1310. The fill hole 1332 allows a substance (e.g., anelectrolyte) to enter the cell 1310.

As shown in FIGS. 23-28, the upper tray 1316 may be used as an assemblytool or fixture according to an embodiment. As can be seen in FIGS.23-24, the cells 1310 having the integral bus bars 1314 are provided inthe upper tray 1316 (which is provided upside down). The alignmentfeatures 1320 (shown as depressions in FIGS. 24, and 27-28) provided inthe upper tray 1316 provide for an assembly/fixturing tool for properlyaligning and orientating the individual cells 1310 into place whenassembling the module 1300. Utilizing the upper tray 1316 as an assemblytool saves time, energy, and money in assembling the battery module1300. As noted above, the bus bars 1314 used in connection with theupper tray 1316 need not be integral with the lid 1312 (i.e., the uppertray 1316 will still be able to properly align and orientate cells 1310having non-integral bus bars 1314).

The cells 1310 (having either an integral bus bar 1314 or a separate busbar coupled to the lid 1312) are provided upside down into the uppertray 1316 (i.e., the end of the cell 1310 having the lid 1312 and busbar 1314 are placed into the upper tray 1316). The bus bar 1314 of eachindividual cell 1310 will be aligned for proper coupling with theterminal 1328 of another cell 1310 (or to other components of thebattery module 1300 or battery system). Additionally, the wall features1322 of the upper tray 1316 may aid in properly locating the individualcells 1310.

Once the cells 1310 are properly located in the upper tray 1316, thebottom tray 1318 is assembled to the cells 1310 (again, upside down).The bottom tray 1318 may have a seal 1330 provided on it to seal thelower end of the cells 1310 (as shown in FIG. 21). The battery module1300 is then turned right side up where the bus bars 1314 are thencoupled to their respective terminal 1328 (e.g., by a fastener, bywelding, etc.).

As noted above, different embodiments of the battery module 1300 mayinclude different numbers or arrangements of the cells 1310 disposedtherein. In some embodiments, the cells 1310 may be arranged in a mannerthat minimizes the space taken up by the cylindrical cells 1310. Toaccomplish this, the cells 1310 may be arranged in two or more rows, asshown in FIG. 22 for example, and the cells 1310 in one row may beoffset from the cells 1310 in an adjacent row so that more cells 1310can be packaged into a closer space. The bus bars 1314 may be sizedappropriately for this type of arrangement.

Although the embodiments of FIGS. 21-24 involve an arrangement of twelvecylindrical battery cells 1310, other numbers of cells 1310 may beutilized in different embodiments. For example, it may be desirable forthe battery module 1300 to include thirteen cells 1310 instead oftwelve, as shown in FIG. 29, to reach a desired power output for thebattery module 1300. Specifically, the nominal voltage of each cell 1310may be approximately 3.65V for NMC and NCA chemistries, although thevoltages may vary with state of charge and other parameters. Thirteen ofthese cells 1310 would yield a nominal voltage of approximately 48V. Inother embodiments, different chemistries of the cells 1310 could havedifferent voltages and, thus, may result in a different number of cells1310 in the battery module 1300. For example, iron phosphate cells,which may have less variation in voltage than the NMC/NCA cells, have anominal voltage of approximately 3.2V, and fifteen of these cells wouldyield a nominal voltage of approximately 48V.

As illustrated in FIG. 29, the cells 1310 are arranged into three rows1350, 1352, and 1354. The first row 1350 includes four cells 1310, thesecond row 1352 includes five cells 1310, and the third row 1354includes four cells 1310. In other embodiments, however, the five cells1310 may be located in the first row 1350 or the third row 1354. Thesecond row 1352 is disposed between and adjacent to the first and thirdrows 1350 and 1354. Again, the cells 1310 in each row are staggeredrelative to the cells 1310 in adjacent rows. That is, the cells 1310 inthe second row 1352 are staggered relative to the cells 1310 in both thefirst row 1350 and the third row 1354, allowing for tighter packing ofthe cells 1310 within the battery module 1300.

As discussed above, the cells 1310 may be electrically coupled to eachother (e.g., in series) to provide a desired voltage output throughterminal connections (not shown) of the battery module 1300. The batterymodule 1300 includes two end cells 1310A and 1310B, one at each end ofthe electrically coupled string of battery cells 1310. These end cells1310A and 1310B may be used to couple the rows of cells 1310 to thepositive and negative terminal connections of the battery module 1300.In some embodiments, the terminal connections to which the end cells1310A and 1310B are coupled may include a connection between the cells1310 in the illustrated battery module 1300 and another group of batterycells disposed in an adjacent battery module of a larger battery system.

Between these two end cells 1310A and 1310B are a number (e.g., eleven)of intermediate cells 1310 that help to increase the voltage differenceavailable through the terminal connections of the battery module 1300.In some embodiments (e.g., FIGS. 30 and 31), the end cells 1310A and1310B may be disposed one at each end of the same row (e.g., second row1352) of cells 1310. In embodiments where the battery module 1300functions as a standalone module, this alignment of the end cells 1310Aand 1310B may allow for simpler assembly of the battery module 1300,since symmetrical terminal conductors can transfer the power from thecells 1310 to external battery terminals. In embodiments where thebattery module 1300 is coupled to other battery modules, the aligned endcells 1310A and 1310B may facilitate relatively easy connection of thebattery modules, since the end cells 1310A and 1310B of all the modulesare aligned with each other. In other embodiments (e.g., FIG. 29),however, the battery module 1300 may include one end cell 1310B in thesecond row 1352 and the other end cell 1310A in either the first row1350 or the third row 1354. In this case, the battery module 1300 may beequipped with asymmetrical terminal conductors for transmitting thepower to terminals of the battery module 1300, or to the cells 1310 inan adjacent battery module 1300.

In the illustrated embodiment of FIG. 29, the cells 1310 areelectrically coupled via the bus bars 1314 across the three rows 1350,1352, and 1354 in a zigzag pattern. More specifically, the cells 1310are oriented such that the intermediate cells 1310 are connected in apattern that snakes back and forth between the cells 1310 in each of thedifferent rows while traversing along a length of the rows. Each of theintermediate cells 1310 located in the first row 1350 are coupled (viabus bars 1314) between an adjacent cell 1310 in the first row 1350 and acell 1310 in the second row 1352. Each intermediate cell 1310 located inthe second row 1352 is coupled between a cell 1310 in the first row 1350and a cell in the third row 1354. Further, each intermediate cell 1310located in the third row 1354 is coupled between an adjacent cell 1310in the third row 1354 and a cell 1310 in the second row 1352. Otherarrangements of battery modules 1300 that utilize multiple rows of cells1310 coupled together may feature similar zigzag patterns of bus barconnections between the cells 1310, in other embodiments.

The three row zigzag pattern of connecting the cells 1310 via the busbars 1314 in FIG. 29 is also used in the embodiment of the batterymodule 1300 shown in FIG. 22. This embodiment has twelve cells 1310coupled together, four cells 1310 in each of three separate rows. Thus,presently disclosed battery modules 1300 may include cells 1310 that arecoupled together via flanged bus bars 1314 in the above describedpattern, regardless of whether the total number of battery cells 1310 istwelve, thirteen, or some other number.

Other zigzag patterns may be employed in three-row arrangements of thebattery cells 1310. For example, FIG. 30 illustrates one sucharrangement of cells 1310 that follows a similar zigzag pattern as theembodiment of FIG. 29, with a slight change at the negative end (e.g.,toward end cell 1310B). This arrangement of the cells 1310 positions theend cell 1310B at the negative end of the battery module 1300 intoalignment with the end cell 1310A at the positive end. Both of these endcells 1310A and 1310B are in the third row 1354, so that symmetricalterminal conductors can couple the battery cells 1310 with externalbattery terminals or adjacent battery modules.

In still further embodiments, other variations of zigzag patterns may beused for electrically coupling the offset cells 1310 in multiple rows.As an example of this, FIG. 31 shows another embodiment of the batterymodule 1300 that includes thirteen cells 1310 for providing a desiredvoltage drop across the battery module 1300. The illustrated embodimentincludes a first row 1360 of seven cells 1310 and a second row 1362 ofsix cells 1310. As discussed above, the cells 1310 in the first row 1360are offset from the cells 1310 in the second row 1362 to allow arelatively efficient use of space for packaging the cells 1310 withinthe battery module 1300.

In the illustrated embodiment of FIG. 31, the cells 1310 are coupledtogether via the bus bars 1314 in a different zigzag pattern than thepattern described above with reference to FIG. 29. Specifically, theillustrated zigzag pattern alternates between battery cells 1310disposed in the first row 1360 and battery cells 1310 disposed in thesecond row 1362. This arrangement may provide an adequate amount ofspace between the different bus bars 1314 that are used to connect thecells 1310. A similar zigzag pattern may be used in embodiments of thebattery module 1300 that include twelve cells 1310 coupled together anddisposed in two rows. It should be noted that, in some embodiments, thebus bar 1314 extending from the end cell 1310A may be oriented with therow 1360, as indicated by reference number 1363. This aligns the bus bar1314 extending from the end cell 1310A at the positive end of thebattery module with the end cell 1310B at the negative end. As discussedabove, this alignment may enable relatively easy and symmetricalassembly of the battery module 1300 or group of battery modules 1300.

It should be noted that the arrangements of cells 1310 described abovefeature the cells 1310 oriented such that the bus bars 1314 arepositioned at relative angles to each other. These angles are smallenough that a zigzag pattern can be used for connecting the cells 1310,and the angles are large enough that the bus bars 1314 do not intersector touch one another. In the illustrated embodiments of FIGS. 22, 29,30, and 31, the cells 1310 are oriented such that the bus bars 1314corresponding to each pair of adjacent cells 1310 that are coupledtogether are offset by an angle of either approximately 60 degrees orapproximately 120 degrees. The term approximately in this instance meanswithin ten degrees. FIGS. 29 and 30 illustrate pairs of adjacent busbars 1314 that are oriented with an offset angle 1364 of approximately60 degrees from each other. In addition, other pairs of adjacent busbars 1314 in these embodiments are oriented with an offset angle 1366 ofapproximately 120 degrees from each other. In the embodiment of FIG. 31,however, every adjacent pair of bus bars 1314 is oriented with an offsetangle 1368 of approximately 60 degrees from each other. In theillustrated embodiments, there are no two adjacent bus bars 1314 thatare entirely aligned with each other.

It should be noted that certain features disclosed with reference toFIG. 21 may be present in battery modules 1300 having any of the abovedescribed cell arrangements. That is, the battery module embodimentsillustrated in FIGS. 29 and 30 may also include the upper tray 1316 withcell alignment features 1320, and the lower tray 1318 with the chamberand the seal 1330. In addition, other embodiments of battery modules1300, which may have different numbers of cells 1310 or rows of cells1310 coupled together, can be oriented according to the zigzag patternsdescribed above, and may include the tray 1316 and/or the chamber aswell.

According to one embodiment, a battery module includes a plurality ofelectrochemical cells provided in between a bottom tray and an uppertray. The electrochemical cells may include a housing having a tubularmain body, a bottom, and a lid. The bottom may include a vent feature toallow venting of gases and/or effluent from inside the housing. The lidmay include a first terminal that is insulated from the lid and a busbar that is integral to the lid. The integral bus bar may serve as asecond terminal of the cell. The battery module may also include a sealprovided between the lower end of the cell and the lower tray to seal achamber configured to receive vented gases from the cells. The uppertray may include features and/or cutouts to help properly align andorientate the cells having integral bus bars.

According to another embodiment, the battery module includes a pluralityof electrochemical cells provided in between a first structure and asecond structure. Each of the electrochemical cells includes a featureextending from a top of the electrochemical cells, the featureconfigured to electrically couple the electrochemical cell to a terminalof an adjacent electrochemical cell or other component of the batterymodule. The first structure includes features to properly orientate eachof the electrochemical cells.

According to another embodiment, a method of assembling a battery moduleincludes providing a plurality of electrochemical cells in a firststructure. Each of the plurality of electrochemical cells has a lidhaving an integral bus bar. The first structure has features to properlyorientate the integral bus bars of each of the plurality ofelectrochemical cells. The method further includes providing a secondstructure over the ends of the electrochemical cells.

One advantageous feature of providing terminals that are integrallyformed with a cover, lid, or container for a battery or cell is that theneed to separately manufacture and couple the terminal to the cover,lid, or container is eliminated. In this manner, labor and manufacturingcosts may be reduced as compared to other cells in which terminals areseparately manufactured from the lid, cover, or container (e.g., byeliminating steps in the manufacturing operation). Additionally,providing terminals that are integrally formed reduces the opportunityfor failure modes to take effect (e.g., because the terminal is notwelded to the cover or container, there is not a weld point which may bea point of electrical shorting or failure)

According to another embodiment, a battery module includes a pluralityof electrochemical cells provided in at least two rows such that thecells in each row are offset from the cells in adjacent rows. Theplurality of cells are electrically coupled to each other to output avoltage drop across two terminal connections of the battery module. Someembodiments may include an arrangement of twelve or thirteen total cellsdisposed in the rows. In some embodiments, the battery module includestwo rows of cells that are connected in a zigzag pattern. In otherembodiments, the battery module includes three rows of cells that areconnected via bus bars or integral terminals extending from one cell tothe next. More specifically, battery cells located in a first row may becoupled between an adjacent cell in the first row and a cell in thesecond row. Battery cells located in the second row may be coupledbetween a cell in the first row and a cell in the third row, and batterycells located in the third row may be coupled between a cell in thesecond row and an adjacent cell in the third row. The offset anglesbetween adjacent bus bar terminals in each of the disclosed cellarrangements may enable a relatively space efficient packaging of thecells within the battery module.

While only certain features and embodiments of the disclosed embodimentshave been illustrated and described, many modifications and changes mayoccur to those skilled in the art (e.g., variations in sizes,dimensions, structures, shapes and proportions of the various elements,values of parameters without materially departing from the novelteachings and advantages of the subject matter recited in the claims.The order or sequence of any process or method steps may be varied orre-sequenced according to alternative embodiments. It is, therefore, tobe understood that the appended claims are intended to cover suchmodifications and changes as fall within the true spirit of thedisclosure. Furthermore, in an effort to provide a concise descriptionof the embodiments, all features of an actual implementation may nothave been described (i.e., those unrelated to the presently contemplatedbest mode of carrying out the disclosed embodiments, or those unrelatedto enabling the claimed embodiments). It should be appreciated that inthe development of any such actual implementation, as in any engineeringor design project, numerous implementation specific decisions may bemade. Such a development effort might be complex and time consuming, butwould nevertheless be a routine undertaking of design, fabrication, andmanufacture for those of ordinary skill having the benefit of thisdisclosure, without undue experimentation.

1. A battery module, comprising: a plurality of battery cellselectrically coupled between a first terminal connection and a secondterminal connection of the battery module and disposed in a first row, asecond row, and a third row, wherein the second row is disposed betweenand adjacent to the first and third rows, and wherein the battery cellsin the second row are offset relative to the battery cells in the firstand third rows; wherein the plurality of battery cells comprises a firstend battery cell electrically coupled to the first terminal connection,a second end battery cell electrically coupled to the second terminalconnection, and intermediate battery cells electrically coupled to eachother between the first and second end battery cells; wherein eachintermediate battery cell in the first row is electrically coupled to anadjacent battery cell in the first row and to a battery cell in thesecond row, each intermediate battery cell in the second row iselectrically coupled to a battery cell in the first row and to a batterycell in the third row, and each intermediate battery cell in the thirdrow is electrically coupled to a battery cell in the second row and toan adjacent battery cell in the third row.
 2. The battery module ofclaim 1, wherein each of the plurality of battery cells comprises acover and an integrally formed first terminal that extends from thecover outward, wherein the first terminal is configured to be coupled toa second terminal on an adjacent battery cell or to a terminalconnection of the battery module.
 3. The battery module of claim 1,wherein the plurality of battery cells are cylindrical battery cells. 4.The battery module of claim 1, wherein the plurality of battery cellscomprise a total of twelve battery cells with four battery cells in eachof the first, second, and third rows.
 5. The battery module of claim 1,wherein the plurality of battery cells comprises a total of thirteenbattery cells with four battery cells in the first row, five batterycells in the second row, and four battery cells in the third row.
 6. Thebattery module of claim 1, wherein each of the plurality of batterycells comprises: a housing having a central longitudinal axis; a covercoupled to the housing; a first flange integrally formed with the coverand configured to act as a first terminal for the battery cell, whereinthe first flange comprises a first portion that extends generallyparallel to the central longitudinal axis of the housing, and a secondportion that extends outwardly beyond the housing in a directionperpendicular to the central longitudinal axis of the housing; and asecond terminal extending from the cover and electrically isolated fromthe first flange.
 7. The battery module of claim 1, wherein the firstend battery cell and the second end battery cell are disposed in thesame row.
 8. The battery module of claim 1, wherein the first endbattery cell is disposed in the second row and the second end batterycell is disposed in the first row or the third row.
 9. The batterymodule of claim 1, comprising a tray with alignment features configuredto align the plurality of battery cells and bus bars for electricallycoupling the battery cells in a desired orientation relative to eachother.
 10. The battery module of claim 9, wherein the tray comprisesapertures formed therethrough, wherein the apertures are configured toexpose a connection point between the bus bars and the battery cells tofacilitate assembly of the battery module.
 11. The battery module ofclaim 1, comprising a lower structure configured to hold the pluralityof battery cells therein, wherein the lower structure comprises achamber for receiving gases vented from one or more of the plurality ofbattery cells.
 12. The battery module of claim 1, wherein at least oneof the first terminal connection and the second terminal connectioncomprise a connection between the plurality of battery cells in thebattery module and another plurality of battery cells disposed in anadjacent battery module.
 13. A battery module, comprising: a pluralityof battery cells disposed in at least two rows, wherein the batterycells in adjacent rows are offset from one another; wherein each of theplurality of battery cells comprises a cover, a first terminal, and asecond terminal, wherein the first terminal extends from the coveroutward in a direction perpendicular to a longitudinal axis of thebattery cell and is coupled to a second terminal on an adjacent batterycell; wherein the plurality of battery cells are oriented such that thefirst terminals corresponding to each pair of adjacent battery cellsthat are coupled together are offset by an angle of either approximately60 degrees or approximately 120 degrees.
 14. The battery module of claim13, wherein the first terminal of each of the plurality of battery cellsis integrally formed with the corresponding cover.
 15. The batterymodule of claim 13, wherein the plurality of battery cells comprisestwelve battery cells electrically coupled together.
 16. The batterymodule of claim 13, wherein the plurality of battery cells comprisesthirteen battery cells electrically coupled together.
 17. The batterymodule of claim 13, wherein the plurality of battery cells are disposedin two rows and the first terminals corresponding to every pair ofadjacent battery cells that are coupled together are offset by an angleof approximately 60 degrees.
 18. The battery module of claim 13, whereinthe plurality of battery cells are disposed in three rows comprising afirst row, a second row, and a third row.
 19. The battery module ofclaim 18, wherein the battery cells disposed in the first row areelectrically coupled between battery cells in the first row and thesecond row, the battery cells disposed in the second row areelectrically coupled between battery cells in the first row and thethird row, and the battery cells disposed in the third row areelectrically coupled between battery cells in the second row and thethird row.
 20. The battery module of claim 13, wherein the plurality ofbattery cells comprises a first end battery cell at one end and a secondend battery cell at an opposite end, wherein the first and second endbattery cells are configured to be coupled to terminal connections ofthe battery module.
 21. The battery module of claim 20, wherein theterminal connections of the battery module comprise connections tobattery cells disposed in adjacent battery modules within a batterysystem.
 22. A battery module, comprising: a plurality of battery cellsdisposed in at least two rows, wherein the battery cells in adjacentrows are offset from each other; wherein each of the plurality ofbattery cells comprises a cover, a first terminal, and a secondterminal, wherein the first terminal extends from the cover outward tobe coupled to a second terminal on an adjacent battery cell; wherein theplurality of battery cells are electrically coupled to each other in azigzag pattern via the first and second terminals.
 23. The batterymodule of claim 22, wherein the plurality of battery cells are disposedin two rows, and wherein the plurality of battery cells are electricallycoupled in a zigzag pattern that alternates between a battery cell in afirst row and a battery cell in a second row.
 24. The battery module ofclaim 22, wherein the plurality of battery cells are disposed in threerows, and wherein the plurality of battery cells are electricallycoupled in a zigzag pattern such that: a battery cell in a first row iscoupled between an adjacent battery cell in the first row and a batterycell in the second row; a battery cell in the second row is coupledbetween a battery cell in the first row and a battery cell in the thirdrow; and a battery cell in the third row is coupled between a batterycell in the second row and an adjacent battery cell in the third row.25. The battery module of claim 22, wherein the first terminal of eachof the plurality of battery cells comprises a flange integrally formedwith the cover.
 26. The battery module of claim 25, wherein the flangecomprises a first portion that extends generally parallel to the centrallongitudinal axis of the housing, and a second portion that extendsoutwardly beyond the housing in a direction perpendicular to the centrallongitudinal axis of the housing.
 27. The battery module of claim 22,wherein the plurality of battery cells comprises twelve or thirteencylindrical battery cells.